<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>购物车</title>
    <style>
      thead {
        background-color: #f5f5f5;
      }
      th,
      td {
        border: 1px solid #aaa;
        padding: 8px 12px;
        text-align: center;
      }
    </style>
  </head>
  <body>
    <table>
      <thead>
        <tr>
          <th>编号</th>
          <th>书籍名称</th>
          <th>出版日期</th>
          <th>价格</th>
          <th>购买数量</th>
          <th>操作</th>
        </tr>
      </thead>
      <tbody></tbody>
    </table>
    <h2 class="price">总价格:¥<span class="price-count">0</span></h2>
    <script>
      //1.先拿到数据
      let books = [
        {
          id: 1,
          name: '《算法导论》',
          date: '2006-09',
          price: 85.0,
          count: 3,
        },
        {
          id: 2,
          name: '《UNIX编程艺术》',
          date: '2006-02',
          price: 59.0,
          count: 2,
        },
        {
          id: 3,
          name: '《编程珠玑》',
          date: '2008-10',
          price: 39.0,
          count: 5,
        },
        {
          id: 4,
          name: '《代码大全》',
          date: '2006-03',
          price: 128.0,
          count: 8,
        },
      ];
      var tbody = document.querySelector('tbody');
      var prices = document.querySelector('.price-count');
      var rows = tbody.rows;
      console.log(rows);
      books.forEach((item) => {
        tbody.innerHTML += `
                  <tr>
                      <td>${item.id}</td>
                      <td>${item.name}</td>
                      <td>${item.date}</td>
                      <td>${item.price}</td>
                      <td>${item.count}</td>
                     <td><button class="delOne">删除</button></td>
                  </tr>
              `;
      });

      tbody.addEventListener('click', (e) => {
        if (e.target.className === 'delOne') {
          e.target.parentNode.parentNode.remove();  
          all -=  e.target.parentNode.parentNode.children[3].innerHTML* ( e.target.parentNode.parentNode.children[4]).innerHTML

        }
      });
      let all = 0
      for (var i = 0; i < rows.length; i++) {
        // 拿到第三个子节点
        var res = rows[i].children[3].innerHTML;
        //  拿到第四个子节点
        var num = rows[i].children[4].innerHTML;
        // 相乘
        var num2 = res * num;
        console.log(num2);
        // 相加
        all += num2;
        console.log(all);
        // 渲染
        prices.innerHTML = all;
      }
    </script>
  </body>
</html>
